Dynamic loud-speaker



May 6, 1930. PREATOR ET AL DYNAMIC Ldun SPEAKER Filed Mar ch 2, 1929fiP/eevqrae, 37 4/ 0.165554 Patented May 6, 1930 U l T E D S T A T E SPATENT OFFICE FREDERICK FBEA'I'OB AND DON R. SEELY, F SALT LAKE CITY,UTAH, ASSIGNOBS TO THE UTAH RADIO PRODUCTS GDMPANY, OF SALT LAKE CITY,UTAH, A. GORGEO- DYNAMIC noun-srnannn Application filed larch e, 1929.Serial No. 348,942.

This invenfion relates to a dynamic loud speaker, and its principalobjects are: First. To prevent the breaking of the moving coil leads.

Second. To make savings in the cost of constructing and assembling.

Third. To add materially to the life of the delicate working parts ofthe speaker mechanism.

Fourth. To preserve the structural integrity of the vibratory system, nomatter what the climatic conditions may be.

Under even date herewith, that is to say March 2, 1929, Serial No.343,941, a separate wand co-pending application for patent entitledMethod of assembling vibratory systems was filed. In the said separateapplication a method of assembling the vibratory system of the presentinvention is described.

2 and claimed. In loud speakers of the dynamic type, the moving orso-called Fvoice coil is usually made oi fiber or similar materialrigidly held in a resilient spider, so that the coil may be vibratedrelatively tothe pole pieces, whereby sound impulses are imparted to theconical d1aphragm, the smaller end of which is attached to the coilmounting.

Usually, the spider is made in one piece 39 and is composed of acircular hub surrounded by an elongated rim, the hub and rim beingspaced annularly apart from each other, but connected by substantiallyradial arms. I

The extremities-of the spider along the line of its elongation, areremote from the arms, and are rigidly held ina stationary part of thespeaker structure. This results in allowing the hub and the centralportion of therimto vibrate freely, but makes it necessary I for theleads by which electric current is con- I ducted to the coils, to bridgea gap between the moving part of the spider and a stationary part of thespeaker structure. Hence, the leads are subjected to incessant movementwhen the coil is vibrating, thus causing the metalin the leads tocrystallize and break after a comparatively short time. This, of course,stops the functioning of the entire mechanism, and makes it a visable tosend rical sections or semi-spiders. These semispiders we insulate, andmake parts of the electrical circuit by means of which the coil isenergized. Each semi-spider necessarily has a semi-hub and a semi-rim.

The circuit is formed by attaching the two leads from the coil to thetwo semi-hub portions, and the two input lines to the two semirimportions. By this means, current is conducted between the stationaryparts of the semi-spiders and the movable parts thereof, through thespider structure itself, while the fine wires of the input linesterminate at the stationary parts of the semi-spiders and are notsubjected to any objectionable motion whatsoever.

Essentially, the semi-spiders serve as supporting and spacing membersfor the moving coil and its mounting.

The features of this invention, for which the protection of LettersPatent ofthe United States is desired, are collectively grouped in theclaims concluding this specification.

' In the drawing, which illustrates merely one embodiment of thisinvention,

Fig. l-repre'sents a longitudinal center section taken on line 1-1, Fig.2, part of the cone diaphragm being broken away;

Fig. 2, an elevation in the direction of arrow 2, Fig. 1, parts in theforeground to the left of line 2-2, Fig. 1, being omitted;

Fig. 3, a section on line 3-3, Fig. 2;

Fig. 4, an enlargement of the central portion of Fig. 1, showing most ofthe parts in elevation instead of in section;

Fig. 5, a detail of substantial? the portlon enclosed by the broken line5 in ig. 1, drawn to tweak considerably enlarged;

Fig. 6, a view in erspective showing a detail of the semi-hu broken awayfrom the semi-spiders; and v i pole piece or core (not shown). Upon theopposite face of the annular pole piece may be secured the mounting ring24, this being held by the screws 25 passing through the annular polepiece.

Carried by the mounting ring 24 and insulated therefrom by the fiberwashers 26, is a spider composed of the two preferably symmetrical but,opposite sections, or substantially semi-spiders 27 and 27-1, thesebeing separated from each other by cutting out a narrow strip from theoriginal spider stamping to define gaps 28 and 29.

Each spider section is composed of. the semi-rim 30, the arm 31 and thesemi-hub 32 which may carry the laterally projecting semi-flange 34. Thespider is mounted on the cylindrical paper sleeve 35 so that thesemi-flanges 34 shall rest upon and be concentric with the sleeve 35.The spider may be rigidly secured to the sleeve 35 by means of thewrapped layers of paper 36 and 37, Fig. 5. At 38 there may be a softpaper washer interposed between the edges of the layers 36 and 37 andsemi-hubs 32, as a cushion. Spaced apart from the spider and wound onthe sleeve 35 is the coil 39, this being held in place by paperwrappings 40 and 41'.

The ends of the spider areclamped in place on the mounting by means ofthe screws 42 bearing down on the fiber washers 43. The screws 42 areinsulated from the spider, by the fiber sleeves 45.

Leads 46 and 47, from the coil, may beattached to the correspondingsemi-hubs by drops of solder 48. The spider semi-rims, at one of theirstationary extremities, for instance 301, may have the lugs49, to whichare attached the respective input terminals 51 and 52 by means of dropsof solder 53.

The usual cone diaphragm 56, having an inwardly projecting hub 57, maybe secured upon the paper wrappings 37 the outer rim of the cone (notshown) being mounted in the usual manner.

In order to afford greater security in attaching the spider semi-hubs tothe sleeve 35, these may be made in the form shown in Fig. 7, where thesemi-hubs 32-1 have, instead of a continuous flange, what may be calleda broken flange, this having portions cut out so as to have lugs 58spaced apart from one another. The recesses retain a certain amount ofglue or cement, which when dry, forms interlocking masses cooperatingwith the lugs 58, to hold the hubs in place u on the sleeve 35 andwithin the wrappings 3 While a specific embodiment of this invention isherein shown and described,'it is to be clearly understood that wereserve to ourselves the right to make such differences and variationsin the construction and arrangement of the details of our device as maybe suggested and demanded by the development and progress of the art orarts with which this invention is most closely identified. It is impliedthat such cliiierences and variations however, shall come within thescope of the accompanying claims.

Having fully described our invention what we claim is:

1. A dynamic loud speaker comprising a pole piece, a spider composed oftwo electroconductive sections spaced apart longitudinally and insulatedfrom each other, and spaced apart and insulated from said pole piece, avoice coil mountin secured in said. spider, a volce 0011 earned y saldvoice-coil mounting, one lead from the voice coil connected to one ofsaid spider sections, the other lead of said voice coilattached to theother spider section, and input leads connected to the respective spidersections.

2. A dynamic loud speaker comprising a vibrator y spider, said spidercomposed of two electro-conductive parts spaced apart from each other, acoil carried by said spider, one terminal of said coil attached to oneof said spider parts, the other terminal ofthe said coil attached to theother part of said spider parts, and electric'input leads attached tothe two respective spider principal parts.

3. A. vibratory system comprising a spider composed of semi-hubs spacedapart from each other and semi-rims spaced apart from each other andfrom said semi-hubs, a vibrating member supported in said semi-hubs, anda support for said semi-rims.

4. A vibratory system comprising two' semi-spiders spaced apart fromeach other longitudinally, said semi-spiders having hub portions, flan eportions projecting laterally from said hu -portions, a cylindricalvibratory member positioned in said hub portions, and wrappings of sheetmaterial extendin around said vibratory member and aroun said flangeportions.

5. A dynamic loud speaker comprising a vibratory s ider, said spidercomposed of two electro-conductive parts spaced apart from each other, acoil mounting and coil supported by said spider one terminal of saidcoil attached to one of said spider parts, the other terminal of thesaid coil attached to the other of said spider parts, electrical inputleads attached respectively to the said spider parts, a cushioningmember adjacent said spider, and a diaphragm member havin a hub portionpositioned against said on ioning member. a

6. A vibratory system comprising two semi-spiders spaced apart from eachother posed between the edges of said layers and the said hub portions,and a diaphragm member seated around said layers and against saidWasher.

7. In a vibratory system, a spider composed of electro-conductivesemi-spiders spaced apart from each other, each semi-spider comprising asemi-hub and a semi-rim spaced apart from said semi-hub.

8. In a vibratory system, a spider composed of electro-conductivesemi-spiders I spaced apart from each other, each semi-spider comprisinga semi-hub, a semi-rim spaced apart from said semi-hub, and asubstantially cylindrical semi-flange extending laterally fromsaid'semi-hub.

9. In a vibratory system, a spider composed of electro-conductivesemi-spiders spaced apart from each other, each semi-spider comprising asemi-hub, a semi-rim spaced apart from said semi-hub, and asubstantially cylindrical semi-flange extending laterally from saidsemi-hub, said semi-flange composed of a plurality of component sectionsspaced apart from one another.

10. In a vibratory system, a vibratory spider composed of a hub portion,a rin portion spaced apart therefrom, and a su stantially cylindricalflange extending laterally from said hub, said flange consisting of apluralit of elemental sections spaced apart circum erentially fromone'another. .p

In testimony whereof We sign our names hereto. FREDERICK PREATOR.

DON R. SEELY.

